The two glucosyltransferase enzymes of Streptococcus mutans GS5 synthesizing soluble and insoluble glucans respectively will be purified to homogeneity from the extracellular fluids of cells grown in chemically defined media. These two enzymes will be utilized to determine the structural requirements for glucan molecules to adhere to smooth surfaces. Antibodies will be prepared against the two enzymes and utilized to explore the nature of the antigenic determinants on the enzymes. In order to assess the potential value of glucosyltransferase antigens in anticaries vaccines, the antibodies will be examined for their effects on the adherence to smooth surfaces of various serotypes of S. mutans known to inhabit the human oral cavity. In addition, the possible cross-reactivity of these antibodies with various human tissue will be investigated by immunofluorescence. The antibodies will also be utilized to examine the control of glucosyltransferase synthesis by protoplasts and cell-free preparations of S. mutans. The intracellular invertase activity of S. mutans will be purified to homogeneity and utilized to prepare anti-invertase antibodies. This antibody will be used to examine the immunological relationship between the invertase, glucosyltransferases and fructosyltransferase of S. mutans. The extracellular growth medium of S. mutans will also be used as a potential sources of extracellular invertase activity. The relationship of the extracellular and intracellular invertase activities will be explored by comparing the kinetic, physical and and immunological characteristics of the two activities.